Document Type

Journal/Book Title/Conference

Publisher

Spacecraft Charging Technology

Publication Date

4-4-2005

Abstract

A study of the effects of prolonged exposure to the space environment and of charge-enhanced contamination on the electron emission and resistivity of spacecraft materials, the State of Utah Space Environment & Contamination Study (SUSpECS), is planned for flight aboard the MISSE-6 payload. The Materials International Space Station Experiment (MISSE-6) program is designed to characterize the performance of candidate new space materials over the course of approximately four to eight month exposure periods on-orbit on the International Space Station, with a target flight date of mid-2006. The study is conducted by the Utah State University Materials Physics Group, in cooperation with the USU Get-Away Special Program and ATK Thiokol. Electron emission and transport properties of materials are key in determining the likelihood of deleterious spacecraft charging effects and are essential parameters in modeling these effects with engineering tools like NASCAP-2K code. While preliminary ground-based studies have shown that contamination can lead to catastrophic charging effects under certain circumstances, little direct information is presently available on the effects of sample deterioration and contamination on emission properties for materials flown in space. Approximately 40 samples will be mounted on panels on both the ram and wake sides of the ISS. They have been carefully chosen to provide needed information for different ongoing studies and a broad cross-section of prototypical materials used on the exteriors of spacecrafts. Much of the pre-flight testing has already been done in conjunction with previous studies through the NASA Space Environments and Effects Program and other projects. The materials will be tested for resistivity and dielectric strength, and for electron-, ion-, and photon-induced electron emission yield curves and emission spectra. Characterization measurements include optical and electron microscopy, reflection spectroscopy, resistivity and Auger electron spectroscopy. In addition, studies of the service life of composite and ceramic materials of the ATK Thermal Protection Systems and Lightweight Structure Systems

Comments

Paper presented at the Proceedings of the 9th Spacecraft Charging Technology Conference, Epochal Tsukuba, Tsukuba, Japan. PDF available for download through link above.